fix(CalDav): add support for Microsoft time zones

[SebastianKrupinski]

• Resolves: #[Bug]: DateTimeZone::__construct(): Unknown or bad timezone (W. Europe Standard Time) #48079

Summary

• Adds handling of Microsoft time zones, when generating iMip emails
• Corrects some spelling

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[SebastianKrupinski]

/backport to stable30

[ChristophWurst]

Very nice! Thank you

[ChristophWurst]

nitpick: try to avoid this in bug fixes, because it may make the backport process more complicated. I suggest to either have a separate commit for refactorings, which can be left out of the backport, or do this in a separate PR

[SebastianKrupinski]

Okay, I normally don't, I only did it in this fix because this class was only introduced in version 30 and there are no differences.

[ChristophWurst]

Checklist

* Code is [properly formatted](https://docs.nextcloud.com/server/latest/developer_manual/digging_deeper/continuous_integration.html#linting)

* [Sign-off message](https://github.com/src-d/guide/blob/master/developer-community/fix-DCO.md) is added to all commits

*

@SebastianKrupinski please keep the original PR template from https://github.com/nextcloud/server/blob/master/.github/pull_request_template.md. Writing docs is very relevant here. Don't drop this.

[ChristophWurst]

Looks good otherwise

[ChristophWurst]

strict types

[antondollmaier]

As written in #48079, thank you. This MR successfully resolves our issue!

[SebastianKrupinski]

As written in #48079, thank you. This MR successfully resolves our issue!

Thanks for testing, you should see the fix, included in the next release of NC30

[ChristophWurst]

/backport to stable29

[backportbot]

The backport to stable30 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable30
git pull origin stable30

# Create the new backport branch
git checkout -b backport/49459/stable30

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick a9254788 58b04fa7

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/49459/stable30

Error: No changes found in backport branch

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.

[solracsf]

/backport to stable29

[backportbot]

The backport to stable29 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable29
git pull origin stable29

# Create the new backport branch
git checkout -b backport/49459/stable29

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick a9254788 58b04fa7

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/49459/stable29

Error: No changes found in backport branch

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.

[SebastianKrupinski]

/backport to stable29

This does not exist in 29, 30+ only